Selischaet fur drahtlose telegrapeie  h



Oct. 9, 1928.

L. FLEISCHMANN LOUD SPEAKER Filed Nov. 15, 1926 RECEIVE? INVENTORA uoNEL FLelscnMAnN B fjgaj( awd# ORNEY vos lll its GtTiRY'ANY, A. GORPORATN OF @ERMES LOUD Application filed November it, 19%, serial No. id-31u53, and in Germany January 22,

rl`he present invention relates to loud speakers9 oi ieale units in general, and has for its principal object the inethod and means mas in current caused by different sound intensities vvill be carried to a point discharge rather than to a diaphragm. By this means of reproduction of sound. more faithful operation is insured.

ln loud speaker units of the present coininercial type the difficult-y appears to. rest in the fact that the diaphragme which are used to produce the vibrations in the air possess a. certain lnass and a natural elasticity. r.this results in imperfect proportional reproducn tion of the el ctrical excitation because ot the natural frequency of each separate dias phi-aghi.

lt has been lrnoivn for a longl period of time that electro-static point discharges possess the property of imparting a motional impulse to the air, which inotional impulses depend upon the potential at the point as soon as the critical potential is surpassed. For inost gases the critical potential ranges from Q() to 3000 volts.

From the above description it is seen that it is necessary that a pointbe supplied With a constant direct current potential bias which should not exceed a certain minimum Where a discharge is produced, upon which the variable potential of the tone-frequency (audiofrequcncy) Wave is superimposed so as to cause the point to discharge. However, it is also possible to obtain vibrations of the air with the direct current potential bias if point or points are supplied with alternating current of corresponding` potential.

rthe presence of the direct current potential has been found, however, to easily lead to arc discharges Which are accompanied by disagreeable noises. Another object of this invention, therefore, is to eliminate such. a tendency to arcdischarge by introducing a dielectric material possessing an infinitely high or very high resistance between the two electrodes. lhis dielectric material will serve to prevent arcing between the electrodes.

@ne form of electrode which l propose 'to use comprises tivo metal disks, one of which is studded With a relatively large number of sharp'needles. rllo insure the highest possible sound volume, the needles must have definite lengths and must be spaced at definite distances frein one another. lt is suitable to embed the needles partly in insulating material Which can be acconuilished vby passing the electricaV `lv connectedA needles throush a dish of insr ating `a'iaterizd7 instead of rising the metal dish to carry the needles.

'llhe preferred for of iny invention is ilustrated by the single ligure in the accornpanying drawin liefern in' to the dimmingj the energy transmittei-L is received on the antenna from which it is carried to the receiver of any preferred forni. 'llhe audio frequency output is then carrie/l by ineens of conductors -5 to plates l and The plates l and 8 are of metal and spaced at any preferred distance with respect to each other. The plate l provided with a plurality of points 2 Which are carefully constructed and mounted in the plate l so as to be spaced at equal distances a from each other and entend equal distances l) above the surface of the plate l to insure the highest possible sound volume. '.lhe plate l pre "e ably circular and has the i points 2 distributed about its surface With equal spacing between each of the said points.

Surrounding the plate i. and separating` the discharge points 2 from each' other is a disk, casing` or covering' of a dielectric mate* rial l to prevent arcingg)` between the electrodes. The battery or other suitable energy source t5 is connected vith the plates i and 3 through the leads 7' and t3 respectively, and is for the purpose of obtaining the proper potential in the points at all times.

"While l have described only a single detail of my inventioin the saine is capable of being; adapted to other modified forms such as may occur to those skilled in the art and l ain entitled to all modifications thereof that fall fairly within the spirit and scope of my invention as deiined by the appended claims, wherein l. rllhe method of reproducingI sound which comprises superiinposing a variable potential of audio frequency upon a definite potential bias at a point, obtaining` thereby an electrostatic point discharge into the atmosphere and creating; by said electrosts ic point discharge trains of sound ivavls varyingv in proportion to the varying; audio potential.

2. rlihe method of reproducing sound which comprises, receiving radio signals` and converting the same into varying audio pulses, conveying the varying` audio pulses to a point, biasing the point by a definite potential near the critical discharge value and, producing an 'electrostatic point discharge by "he superimposing or" said varying audio pulses upon said biased discharge point, thereby producingl trains of sound waves in the atmosphere proportional to the audio pulses.

3. An arr ngement for reproducing sounds comprising, a plurality of dish electrodes, a plurality el. -equallv spaced points mounted in one of said electrodes, means for producing, a steady bias potential near the critical discliarge value on said points, and means lor superimposine varyingv audio p ulses on said bias potential whereby said electrode pro V*id d with said spaced points will be discharge energy to the other of said electrodes and produce in the atmosphere betnf'een said electrodes a train of sound waves proportional to said audio pulse.

4.r An arrangement ier reproducing sounds comprising, means `for receiving' radio signals and convertingv the same into varying audio pulses,a plurality of spaced electrodes, means for producing al steady potential bias on said electrodes, said bias potential. being near the critical discharge point for said electrode spacing, and means for superimposing` said audio pulses on said biased electrodes w iereby electrostatic point discharge occurs between said electrodes andt trains of sound waves are produced in the 'atmosphere between said electrodes-varying in proportion to said audio pulses.

5. An arrangement for reproducing` sounds comprising,` means for receiving radiosignals and converting the same into varying audio pulses, a plurality of spaced disk electrodes and a layer of atmosphere therebetween, a dielectric material surrounding,- one of said electrodes, a` biasing means for applying a potential approaching adischarge potential on said.

electrodes, means for superimposing said varying` audio potential on said biarei'l electrodes, whereby an electrostatic disclun ,eje occurs between said electrodes and a sound waive is produced in the atmosphere separatiulf: said electrodes. Y

G. in arrangenient tor reproducing sounds con'iprising, a plurality olf disl: electrodes :ce paratedby a layer of atmosphere, an insulating' material surrounding one oi sai d deci rodea", a

plurality oit' spaced discharge points mounted in said last named disk and extending; through said insulating material, means Yfor impressing a steady bias potential near the critical discharge value upon said points, means :for receiving radio frequency signals and convertin` the same into varying' audio :frequency pulses, and means iter superimposinl; said varying audio pulses upon said potentially biased electrodes for prodrufingv point discharge between said electrodes, \\lu uebj,f sound waves are circulated in the atmosphere between said electrodes which correspond io the received si gnals.

7. in inertialess speale system comprising a corona discharge device, and a source i iE sound varied electrical energy coupled to said device to modulate the intensity ot the corona.

8. An inertialess speaker sj teni compris ing,l a corona discharge device, :in electrical circuit including` a source oi nninodulaicd electrical energy -lier energizni, said device, and a source ci sound variedelectrical energy coupled to said circuit to modulate the intensity o'i the corona.

9. ln combination, an inertiuless speaker comprising a corona discharge device located in the air medium which is to curry the sound, a source of electrical energy for energizing said device at a constant value, and a source oi modulated electrical energy arranged to mod ulate the resultant corona.

lO. ln combination, an inertialcss speaker comiinisinc` a corona discharge device, und means including radio receiver to energize said device.

LIGNEL llrElSCl'lllili/lldltl. 

